The Oswego County Industrial Development Agency's ranking as one of the top 10 givers of tax exemptions in New York is accurate but misleading, the county's top economic development official says.

Don't get him wrong. L. Michael Treadwell, executive director of Operation Oswego County, the county's economic development arm, said he wants the world to know that the county is aggressive in its recruitment of employers.

But the report released by the state Authorities Budget Office on Tuesday gives the impression that the county is handing out far more tax exemptions than it really is, Treadwell said.

The report issued says the Oswego County IDA issued $68 million in tax exemptions to businesses from 2008 through 2011. That put it ninth among the state's 109 industrial development agencies in terms of tax giveaways.

Treadwell does not dispute the accuracy of the report's numbers. In fact, they come from data provided by the Oswego County IDA itself.

But $61 million of the $68 million in tax exemptions given out by the IDA went to just one project -- the 1,042-megawat, gas-fired power plant built by Sithe Energies in Scriba in the early 1990s.

Treadwell said the plant cost $800 million to build and was initially assessed at $650 million. However, he said the plant, known as Independence Station, has been worth far less than $650 million for years, he said.

The industrial development agency exempted the power plant from property taxes for 20 years and recently extended the deal for another 18 years. But Sithe -- and later Dynegy Inc. when it bought the plant -- were required to make payments in lieu of taxes.

The amount of the plant's payments was set by a fixed schedule and was not based on the tax assessment on the plant. Currently, those payments amount to $5.47 million a year, making the plant one of the biggest taxpayers in Oswego County.

If the plant was taxed based on the $650 million assessment, it would pay $20.4 million in property taxes a year. So its net tax exemption, after its $5.47 million payment, was about $15 million a year.

The market value of the plant fell substantially over the years, but Sithe and Dynegy never challenged the assessment because their payments in lieu of taxes were not tied to the assessment, Treadwell said.

Denegy recently got around to asking the town to lower the assessment, probably to protect itself in case its tax agreement with the IDA was ever terminated, Treadwell said.

The town lowered the assessment to $200 million. Based on that assessment, annual property taxes on the power plant would be $5.5 million. Since it makes annual payments of $5.47 million, the savings the plant gets from its tax deal now total just $35,000 annually, Treadwell said.